Hyperspectral imaging allows the measurement of spectral characteristics of a scene of interest using a remote sensing system with a large number of spectral bands, each band with a spectral resolution of less than 10 nm. A hyperspectral imager is thus capable of producing a quasi-continuous spectrum of light which can define the chemical composition of elements of the scene of interest via their respective spectral signatures.
Known hyperspectral imagers that comprise tunable wavelength dispersing elements, or filters, lack the switching speed required to spectrally multiplex acquired hyperspectral imaging data. Typically in such hyperspectral imagers, each spectral resolution element is acquired in serially, and each spectral resolution element amounts to a small fraction of the total hyperspectral cube. The integration time associated with the serial acquisition of each spectral resolution element can lengthen the acquisition time required to acquire and assemble the hyperspectral cube.
The acquisition time exhibited by known tunable hyperspectral imagers makes them unsuitable for uses where rapid acquisition of the hyperspectral cube, for instance by spectrally multiplexing the hyperspectral imaging data, is necessary for optimum results. For example, acquisition of the hyperspectral cube via spectral multiplexing is desirable for hyperspectral imaging from a moving platform, such as an aircraft. This is because rapid acquisition of the hyperspectral cube minimizes artifacts caused by the motion of the airborne platform during the acquisition.
Therefore, what is desirable is a tunable wavelength dispersing element with high speed switching times, for instance switching times that enable spectral multiplexing of acquired hyperspectral imaging data.